首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   3485459篇
  免费   292816篇
  国内免费   14613篇
耳鼻咽喉   48539篇
儿科学   107136篇
妇产科学   91425篇
基础医学   547773篇
口腔科学   97142篇
临床医学   308910篇
内科学   619686篇
皮肤病学   93164篇
神经病学   298308篇
特种医学   139039篇
外国民族医学   455篇
外科学   544527篇
综合类   107407篇
现状与发展   24篇
一般理论   2270篇
预防医学   284834篇
眼科学   79833篇
药学   243534篇
  23篇
中国医学   10398篇
肿瘤学   168461篇
  2021年   55208篇
  2020年   35194篇
  2019年   58209篇
  2018年   71124篇
  2017年   54246篇
  2016年   60047篇
  2015年   74141篇
  2014年   108394篇
  2013年   173621篇
  2012年   90782篇
  2011年   89877篇
  2010年   115753篇
  2009年   120923篇
  2008年   77555篇
  2007年   81130篇
  2006年   91907篇
  2005年   87221篇
  2004年   89447篇
  2003年   80728篇
  2002年   71059篇
  2001年   109310篇
  2000年   102434篇
  1999年   101359篇
  1998年   65255篇
  1997年   63142篇
  1996年   60665篇
  1995年   56105篇
  1994年   50337篇
  1993年   47025篇
  1992年   71721篇
  1991年   68028篇
  1990年   65006篇
  1989年   64346篇
  1988年   60224篇
  1987年   58849篇
  1986年   56344篇
  1985年   55975篇
  1984年   50496篇
  1983年   45779篇
  1982年   42322篇
  1981年   39794篇
  1980年   37630篇
  1979年   42939篇
  1978年   37357篇
  1977年   34271篇
  1976年   31033篇
  1975年   30691篇
  1974年   32406篇
  1973年   31075篇
  1972年   29505篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Adjuvant irradiation is the standard treatment after breast conservative surgery. Normofractionated regimen with an overall treatment time of 5 to 6 weeks is often considered as a limiting factor for irradiation compliance. In order to answer this issue, moderate and more recently extreme hypofractionated protocols appeared. We report here oncological outcomes and toxicity of hypofractionated breast irradiation. After defining the frame of moderate and extreme hypofractionated breast irradiations based on overall treatment time, patient selection criteria were listed. According to their levels of proof, the results of moderate and extreme hypofractionated breast irradiation were analysed. Overall treatment time for moderate hypofractionated breast irradiation ranged from 3 to 4 weeks, while for extreme hypofractionated breast irradiation, it was less than 1 week. For moderate hypofractionated breast irradiation, whole breast irradiation was currently performed with or without lymph node irradiation. Moderate hypofractionated breast irradiation has proven to be as safe and as efficient as normofractionated breast irradiation with level IA evidence. For extreme hypofractionated breast irradiation, phase III randomized trials confirmed that accelerated partial breast irradiation was non-inferior in terms of local control compared to normofractionated whole breast irradiation (with external beam radiation therapy and multicatheter brachytherapy), with similar acute and late toxicity. While the use of intraoperative breast irradiation remains under debate, new very accelerated partial breast irradiation (overall treatment time not exceeding 2 days) protocols emerged with encouraging results. Accelerated partial breast irradiation is warranted for extreme hypofractionated breast irradiation and is indicated for low-risk breast cancers. Moderate and extreme hypofractionated breast irradiation regimens are validated and can be routinely proposed according to patient selection criteria.  相似文献   
92.
93.
Introduction: Percutaneous renal mass biopsy has evolved over the last decade with improvements on previous pitfalls including low tissue yield, high non-diagnostic rates, and complications. As understanding of tumor biology and natural history of renal cortical neoplasms has improved, percutaneous renal mass biopsy is poised to have an expanding role in an area characterized by individualized management and refined risk stratification.

Areas covered: This review summarizes the evolution of renal mass biopsy to its current state with respect to outcomes, indications, and clinical guidelines.

Expert opinion: With improved understanding of differential biological potential of renal cortical neoplasms combined with technical improvements in diagnostic yield and accuracy, utilization of renal mass biopsy is becoming an important adjunct to patient care in a broad range of clinical scenarios, including active surveillance, thermal ablation, and use of primary systemic therapy in localized and advanced settings.  相似文献   

94.
95.
96.
97.
98.
MicroRNAs (miRNAs) play important roles in prostate cancer development. However, it remains unclear how individual miRNAs contribute to the initiation and progression of prostate cancer. Here we show that a basal layer‐enriched miRNA is required for prostate tumorigenesis. We identify miR‐205 as the most highly expressed miRNA and enriched in the basal cells of the prostate. Although miR‐205 is not required for normal prostate development and homeostasis, genetic deletion of miR‐205 in a Pten null tumor model significantly compromises tumor progression and does not promote metastasis. In Pten null basal cells, loss of miR‐205 attenuates pAkt levels and promotes cellular senescence. Furthermore, although overexpression of miR‐205 in prostate cancer cells with luminal phenotypes inhibits cell growth in both human and mouse, miR‐205 has a minimal effect on the growth of a normal human prostate cell line. Taken together, we have provided genetic evidence for a requirement of miR‐205 in the progression of Pten null‐induced prostate cancer.  相似文献   
99.
100.
Secondary tricuspid regurgitation (TR) caused by right ventricular enlargement in the setting of left heart disease/pulmonary hypertension has been well described. In contrast, that associated with right atrial enlargement—atrial functional TR (AF‐TR)—remains largely underappreciated. AF‐TR most often occurs in the setting of lone atrial fibrillation, although it is also seen in its absence (idiopathic AF‐TR). Several recent studies have found that the prevalence, hemodynamic significance, and prognosis of AF‐TR are not inconsequential, suggesting increased physician awareness of this novel clinical entity is warranted. This article discusses the pathogenesis, echocardiographic findings, and treatment of this underappreciated cause of secondary TR.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号